Commit before generalising picture transformation to alternative

src/Dodge/Update.hs

@@ -75,7 +75,7 @@ update' w = case _menuLayers w of
         . updateSoundQueue
         $ updateCloseObjects w
   where 
-    zoneCreatures = set creaturesZone (IM.foldr creatureInZone IM.empty (_creatures w))
+    zoneCreatures = set creaturesZone (IM.foldl' (flip creatureInZone) IM.empty (_creatures w))
     creatureInZone cr = insertIMInZone x y cid cr
       where 
         (x,y) = crZoneOfPoint $ _crPos cr
@@ -120,7 +120,7 @@ updateLightSources w = set tempLightSources (catMaybes tlss) w'
     (w',tlss) = mapAccumR (\a b -> _tlsUpdate b a b) w $ _tempLightSources w
 
 updateProjectiles :: World -> World
-updateProjectiles w = IM.foldr' (dbArg _pjUpdate) w $ _projectiles w
+updateProjectiles w = IM.foldl' (flip $ dbArg _pjUpdate) w $ _projectiles w
 {-
 Apply internal particle updates, delete 'Nothing's.  -}
 updateParticles :: World -> World
@@ -137,13 +137,13 @@ updateCreatures w = f $ set randGen newG $ set creatures (IM.mapMaybe id crs) w
 {- |
 Apply door mechanisms.  -}
 updateWalls :: World -> World
-updateWalls w = IM.foldr (fromMaybe id . (^? doorMech)) w (_walls w)
+updateWalls w = IM.foldl' (flip $ fromMaybe id . (^? doorMech)) w (_walls w)
 
 ppEvents :: World -> World
-ppEvents w = IM.foldr (\pp w' -> _ppEvent pp pp w') w $ _pressPlates w
+ppEvents w = IM.foldl' (flip $ \pp w' -> _ppEvent pp pp w') w $ _pressPlates w
 
 updateSeenWalls :: World -> World
-updateSeenWalls w = foldr markSeen w wallsToUpdate
+updateSeenWalls w = foldl' (flip markSeen) w wallsToUpdate
   where 
     vPos = _cameraViewFrom w
     wallsToUpdate = concatMap (\p -> visibleWalls vPos (vPos +.+p) $ wallsAlongLine vPos (vPos +.+ p) w)
@@ -190,10 +190,10 @@ clClSpringVel a v b
     radDist = (_clRad a + _clRad b) / 2
 
 simpleCrSprings :: World -> World
-simpleCrSprings w = IM.foldr' crSpring w $ _creatures w
+simpleCrSprings w = IM.foldl' (flip crSpring) w $ _creatures w
 
 crSpring :: Creature -> World -> World
-crSpring c w = IM.foldr' (crCrSpring c) w cs
+crSpring c w = IM.foldl' (flip $ crCrSpring c) w cs
   where 
     cs = creaturesNearPoint (_crPos c) w